The Natural Areas Program and Pesticide Use
April 5, 2014 5 Comments
We recently received a response from Phil Ginsburg, General Manager of the San Francisco Recreation and Parks Department (SFRPD) , to our concerns regarding the “Natural Areas Program” (NAP). We thank him for the detailed response, but we still have a number of points of disagreement.
One of them is herbicide use. His letter states, “As a percentage of our overall total, herbicide usage in the Natural Areas comprises only 4%.”
As readers of this website know, that’s very different from our own analysis. We find that NAP uses nearly as much of the ‘Most Hazardous’ and ‘More Hazardous’ herbicide as the rest of SFRPD (ex Harding Golf Course).
And the discrepancy is the more surprising since the source documents are the same – the Monthly Pesticide Use Reports each section submits.
The graph below compares NAP and other SFRPD (ex Harding Golf Course). Not only is NAP clearly using much more than 4%, it also is the largest user of the Most Hazardous (Tier I) chemicals. (The San Francisco Department of the Environment – SFDoE – produces a “Reduced Risk Pesticide” list each year. This lists pesticides that may be used on city-owned lands, and gives them Tier ratings.)
WHY THE DISCREPANCY?
Since we don’t know how Mr Ginsburg’s percentage is derived, we can only speculate. Some possible reasons:
1) Our numbers leave out Harding Golf Course, but they include it.
Here’s why we exclude it: Harding Park Golf Course is under contract to be maintained to tournament-ready standards. This means it uses a lot of pesticides; but it really is outside SFRPD control if San Francisco is to have a PGA-standard golf course. (The city’s other golf courses, where SFRPD actually can determine pesticide use, actually use very little. Sharp Park, for instance, has used none since August 2010.)
2) Our numbers are for the most recent year, 2013.
Though the phrasing of the sentence suggests that are considering current usage, they may actually have used historic numbers. It’s possible that other sections of SFRPD reduced their herbicide usage, even while NAP’s herbicide usage went up. NAP herbicide use rose annually from 2009 through 2013.
3) We have only considered the chemicals that are most concerning – the “more hazardous” and “most hazardous” herbicides (those the San Francisco Department of the Environment classifies as Tier II and Tier I) and omitted the “least hazardous” ones (Tier III). Possibly SFRPD has included Tier III herbicides. We think this would distort the comparison; it would be like comparing pineapples and hand-grenades.
4) If it’s based on the SF DoE’s new database, it may have data-entry errors, especially for data since 2010 when the new database was instituted. We compiled the
Monthly Pesticide Usage reports ourselves, and re-checked them.
HOW WE GOT OUR NUMBERS
For anyone who wants to replicate our calculations, here’s how we made them:
- We obtained Monthly Pesticide Usage reports from SFRPD under the Sunshine Act. If any of them were unclear, we got clarifications.
- We compiled this data into a spreadsheet. Then we calculated Tier I and Tier II herbicide usage separately for NAP and for all other SFRPD (excluding Harding Golf Course), using SF DoE’s ratings.
- We show “Greenmatch” separately – it’s rated Tier II, but it’s an organic herbicide that is less harmful than most Tier II products. Until 2013, it was rated Tier III, least hazardous.
- [ETA: We calculated the "Active Ingredient" quantity by using conversion factors provided by the manufacturer of each chemical. (These are available online.)]
In the first two months of 2014, NAP was still the major user of Tier I herbicides, using 8 times as much as all the rest of SFRPD ex Harding.